Internal combustion engines combust a fuel and air mixture within cylinders driving pistons to produce drive torque. The engine drives a transmission through a coupling device. In the case of an automatic transmission, the coupling device includes a torque converter. The transmission transfers the drive torque to a driveline through one of a plurality of gear ratios. The transmission shifts between gear ratios based on a shift schedule and vehicle operating conditions.
The transmission typically includes a plurality of clutches that are selectively engaged to establish a desired gear ratio. When shifting between gear ratios, clutch-to-clutch shifts occur. More specifically, at least one clutch is disengaged (i.e., off-going clutch) while another clutch is concurrently engaged (i.e., on-coming clutch). Control of the clutch-to-clutch shift is based on an estimated engine torque (TEST) and other shift parameters including, but not limited to, a clutch fill time, a clutch pressure offset and a clutch full feed fill threshold (FFFT) pressure. TEST is determined using a torque estimating calculation that is based on engine operating conditions. The clutch fill time, the clutch pressure offset and clutch FFFT pressure for each clutch, however, are adaptively learned and updated during vehicle operation.
When the vehicle first rolls off the assembly line and/or service has been performed on the transmission, the shift parameters are set to initial values and do not include the benefit of the adaptive/learned shift control. As a result, the transmission shift quality is not as high as desired. Traditionally, a technician would be required to drive the vehicle over a series of drive cycles to improve the shift quality using the adaptive shift control before providing the vehicle to the customer. Driving the vehicle increases time and cost, and exposes the manufacturer to unnecessary liability.